The present inventive teachings relate generally to a brushless wound field synchronous generator, and more particularly, an overvoltage protection circuit of a rotating diode assembly included in a wound field synchronous generator.
Brushless wound field synchronous generator systems may utilize start inverters to electrically excite the main armature winding during initial engine start. Conventional wound field synchronous generator systems may include a rotating diode assembly, which is traditionally subject to overvoltage stress caused by voltage spikes generated by the start inverter during the engine start. Voltage spikes on the main armature windings may be realized on the rotating diodes. Over time, the overvoltage stress may result in failure of the rotating diode assembly.
In addition, flowing oil that streams past solid surfaces, for example during rotor operation, in the generator may induce an electrostatic charge accumulation (ECA) phenomena. The ECA may build in the rotating diode assembly, thereby resulting in electrostatic discharge (ESD) and causing failure of one or more diodes included in the rotating diode assembly.